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You don't have to look for long to see violent events in the Universe.
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Exploding stars spewing out superheated gas.
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Supermassive black holes ripping material from nearby objects, expelling immense jets as they do so.
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And galaxies torn apart or blended together as they stray just a little too close to one another.
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Merging like the ones in this stunning new image from Hubble.
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Episode 75: Merging galaxies and droplets of star formation
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The Universe is a pretty empty place,
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dotted with galaxies at immense distances from one another.
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But occasionally, two or more galaxies will come close to each other.
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This can lead to them coalescing into one larger body
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An event known as a galactic merger.
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The violent merging process strips some of the gas, dust, and stars away from the galaxies,
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and can alter their appearances dramatically,
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forming huge tails, glowing rings and warped galactic discs.
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In 2008, Hubble team released a set of 59 new images of interacting and merging galaxies,
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showing the vast array of striking shapes these collisions can create.
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This time, Hubble has captured something a little more unusual:
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At the centre of this image lie two elliptical galaxies,
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part of a galaxy cluster known rather prosaically as SDSS J1531+3414.
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This cluster contains so much mass that it has bent light from more distant galaxies
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to form the spectacular blue arcs that surround it.
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The rarity here is that the elliptical galaxies are not only merging,
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which is very unusual,
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but that the merger is rich enough in gas to spark the formation of many new stars.
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These infant stellar superclusters have formed through a process called “beads on a string” star formation,
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which has left them in even clumps strung out on a long, gaseous filament.
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The clumps of stellar infants are visible here as a speckling of bright blue dots.
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Nineteen compact clumps are woven together with narrow filaments of hydrogen gas.
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The star formation spans 100 000 light-years, which is huge, at about the size of our galaxy, the Milky Way.
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The strand is dwarfed, however, by the ancient, giant merging galaxies that it inhabits.
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They are about 330 000 light-years across, nearly three times larger than our own galaxy.
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This is typical for galaxies at the centre of massive clusters, which tend to be the largest galaxies in the Universe.
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These clumps formed as a result of the same fundamental physics that causes rain to fall in droplets, rather than a continuous column.
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The merging system is forming stellar superclusters in equally spaced beads, just as a tap drips evenly spaced water droplets.
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The only real difference is in the underlying force driving the droplet formation
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― surface tension in the falling water is replaced by gravity in the context of the star-forming chain.
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This beautifully illustrates how the laws of physics apply at every scale in our Universe.
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From millimetre rain drops, to a chain of infant star clusters 100 000 light-years across.
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Hubblecast is produced by ESA/Hubble at the European Southern Observatory in Germany.
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The Hubble mission is a project of international cooperation between NASA and the European Space Agency.